A probe into why a £1bn turnover trust failed to recover its waiting times was halted after witnesses could not, or would not, co-operate with investigators, HSJ can reveal.

Barts Health Trust, one of the biggest providers in England, stopped reporting its elective referral to treatment time data in August 2014 and commissioned a report from Verita into the causes of the problems in 2015. Verita submitted its report in “late 2015”.

The review was never completed, and in a statement the trust said this was because it had been “unsuccessful in its efforts to complete the right of reply process with individuals named in the report”. Verita told HSJ it had completed the review but it was up to the trust whether to publish it or not.

A copy of the report’s draft recommendations given to HSJ by the trust said “before December 2014, the [elective recovery] programme leadership had changed multiple times over short time periods”.

The east London provider this month started reporting its referral-to treatment time data for the first time since 2014.

A spokesman confirmed the organisation had carried out clinical harm assessments on 2,000 patients – some of whom had waited more than a year, and some who had been identified as being at high risk of clinical harm. He said none of the 52 week plus waiters had suffered “moderate” or “severe” harm.

HSJ is awaiting confirmation of how many patients came to any harm.

The clinical harm process was overseen by a clinical director at the trust and externally assessed by a team led by NHS England’s medical director for London.

The trust, which sees around 15,877 elective patients a month, still has 36 who have waited more than a year for treatment.

The trust said it would bring the latter number to zero by the end of 2018-19 and that a report on the clinical harm review process would come to the board after that.

The trust was formed in April 2012 from three smaller trusts and the recommendations from Verita’s unfinished report said all three had waiting times problems when Barts Health Trust was created.

The recommendations said the purpose of the investigation was to determine why a plan agreed by the trust in January 2014 “failed to meet its objectives and whether the measures now in place are adequate to improve performance”.

Barts has not provided these parts of the report but the recommendations said the trust was “likely to have spent £6.5m on referral to treatment time recovery and the programme management office in 2015-16.

The recommendations added: “This programme led to significant improvement in the size of the waiting list, improvement in backlog, reduction of the data quality issues and improved user training and understanding the system.”